A Method for estimating the size of a Woodlouse population using UV marker pens.
(The Natural History Museum, London 2007. All Rights Reserved)
After capturing a large sample of woodlice, students use UV security marker pens to label them. These pens are relatively cheap (around £3 each) and are available at many stationers - I got mine from Rymans (the pens from Maplins were less effective). The woodlice can then be released and recaptured a day or two later.
A UV lamp, available for around £20 from several biotech companies (usually used for Bio-Rad 'pGlo' protocol), can then be used to quickly scan the captured woodlice in a darkened room and the marked ones recorded. The recaptured woodlice can then be counted and released, and the population estimated using The Lincoln Index.
Woodlouse seen under UV light
A sample size of around 500 (collected by 15 students) appeared to work quite well. The benefit of using UV markers is that there is no bias in the recapture process. The students also love to see glowing woodlice scurrying around the place! The pens appear to have no detrimental effect on the woodlice - UV woodlice surviving for several days apparently unaffected in the lab.
Maplins UV marker and lamp (about £8 - the lamp works very well; not so sure about the marker pen) Rymans UV security marker pen Edvotek UV lamp Bio-Rad UV lamp Walking with Woodlice The Natural History Museum
A Method for estimating the size of a Woodlouse population using UV marker pens.
(The Natural History Museum, London 2007. All Rights Reserved)
After capturing a large sample of woodlice, students use UV security marker pens to label them. These pens are relatively cheap (around £3 each) and are available at many stationers - I got mine from Rymans (the pens from Maplins were less effective). The woodlice can then be released and recaptured a day or two later.
A UV lamp, available for around £20 from several biotech companies (usually used for Bio-Rad 'pGlo' protocol), can then be used to quickly scan the captured woodlice in a darkened room and the marked ones recorded. The recaptured woodlice can then be counted and released, and the population estimated using The Lincoln Index.
Woodlouse seen under UV light
A sample size of around 500 (collected by 15 students) appeared to work quite well. The benefit of using UV markers is that there is no bias in the recapture process. The students also love to see glowing woodlice scurrying around the place! The pens appear to have no detrimental effect on the woodlice - UV woodlice surviving for several days apparently unaffected in the lab.
Maplins UV marker and lamp (about £8 - the lamp works very well; not so sure about the marker pen)
Rymans UV security marker pen
Edvotek UV lamp
Bio-Rad UV lamp
Walking with Woodlice The Natural History Museum